Provided are a striking device and a natural frequency measuring device capable of simply and accurately measuring a natural frequency of a system including force detector. The striking device includes an arm capable of swinging around a spindle, and a steel ball arranged in an end part of the arm on a side opposite to the spindle. The spindle is supported by a supporting part capable of lifting up and down relative to a post erected on a magnet stand. A supporting part for supporting a supporting plate is arranged at a position in the post and above the supporting part. A permanent magnet is placed above the supporting plate. The steel ball falls down in an arc shape from a standby height position when the permanent magnet is removed.

A head impact test apparatus is configured to enable viewing a head model including a brain component that may be at least partially surrounded by a fluid component and within a skull component. A head model may be a cross-sectional model of a person's head and have a translucent cover extending over the cross-sectional plane to enable viewing and image capture of the components of the head model. A camera may be configured to take a plurality of images during an impact test. These images may be analyzed to determine the acceleration and deformation of the brain component. An impact element is configured to impact the head model and the head model may have any type of helmet thereon. A helmet component may comprise a helmet cover. The test may be used to determine the effectiveness of helmets and helmet covers in reducing brain trauma.

A drop ball test fixture includes a bracket, first stoppers and connecting components. The bracket has bearing surfaces for bearing edges of a panel and to position the panel in a direction parallel to the bearing surfaces. At least part of each of the first stoppers is located above corresponding one of the bearing surfaces. Each connecting component includes a guide rod, a guide groove and a second stopper. The guide groove is formed on corresponding one of the first stoppers. One end of each of the guide rod is connected to the bracket while the other end thereof passes through the guide groove. Connecting structures are provided at different heights of the guide rod, and the second stopper is matched with and connected to corresponding one of the connecting structures at different heights above the guide groove so as to stop the upward movement of the first stopper.

A drop ball test fixture includes a bracket, first stoppers and connecting components. The bracket has bearing surfaces for bearing edges of a panel and to position the panel in a direction parallel to the bearing surfaces. At least part of each of the first stoppers is located above corresponding one of the bearing surfaces. Each connecting component includes a guide rod, a guide groove and a second stopper. The guide groove is formed on corresponding one of the first stoppers. One end of each of the guide rod is connected to the bracket while the other end thereof passes through the guide groove. Connecting structures are provided at different heights of the guide rod, and the second stopper is matched with and connected to corresponding one of the connecting structures at different heights above the guide groove so as to stop the upward movement of the first stopper.

According to the present technology, an impact test in which an impact application member is made to free fall onto a test sample of a plurality of types of rubbers having different physical properties is performed under prescribed test conditions; data for at least one of three items including a loss energy that is absorbed by the test sample when the impact application member collides with the test sample, a thermal energy that is generated at the test sample, and an indentation amount into the test sample by the impact application member is acquired; and an optimal test sample is selected from the respective test samples on a basis of a ranking of the superiority of the respective test samples with respect to the item(s) for which data was acquired.

According to the present technology, an impact test in which an impact application member is made to free fall onto a test sample of a plurality of types of rubbers having different physical properties is performed under prescribed test conditions; data for at least one of three items including a loss energy that is absorbed by the test sample when the impact application member collides with the test sample, a thermal energy that is generated at the test sample, and an indentation amount into the test sample by the impact application member is acquired; and an optimal test sample is selected from the respective test samples on a basis of a ranking of the superiority of the respective test samples with respect to the item(s) for which data was acquired.

An impact test method and an impact test device is provided, wherein an impact application member is caused to fall freely onto a test sample placed on a placement platform. When the impact application member collides with the test sample, an impact force applied to the test sample and an indentation amount of the impact application member with respect to the test sample are measured by a load meter and a displacement meter, respectively. Based on the measured impact force and the measured indentation amount, a calculation unit calculates energy loss absorbed by the test sample when the impact application member and the test sample collide with each other.

An impact test method and an impact test device is provided, wherein an impact application member is caused to fall freely onto a test sample placed on a placement platform. When the impact application member collides with the test sample, an impact force applied to the test sample and an indentation amount of the impact application member with respect to the test sample are measured by a load meter and a displacement meter, respectively. Based on the measured impact force and the measured indentation amount, a calculation unit calculates energy loss absorbed by the test sample when the impact application member and the test sample collide with each other.

A method for testing a helmet for effectiveness of user protection includes moving a load along a predetermined path, supporting a target body at an impact location in the predetermined path, the target body including a head model and a helmet disposed on the head model, and impacting the target body with a force generated by the moving of the load. The impacting of the target body entails contacting the target body with an impactor free to move perpendicularly and tangentially relative to a surface of the target body. The supporting of the target body is at least reduced, if not eliminated, before or during the impact of the impactor with the target body at the location. Forces generated are automatically measured or sensed during the impact of the impactor with the target body at the location.

The disclosure provides solid compositions such as lyophilisates adhered to surfaces such as plasma-treated surfaces and related methods, uses, kits, intermediates, starting materials, and downstream products.